Arrangement provided with a photo-cell and controlling the detecting means and the stop motion in a loom upon breaking of a thread in the warping, weaving and knitting systems

ABSTRACT

In a loom or warping system, a safety arrangement is provided for operating machine-stopping or detecting means whenever a thread breaks. To this end, the sheet of parallel threads is constrained to pass over a braking member, in practice between frictionally acting parallel transverse bars, so that upon breaking of a thread beyond the braking member, said thread may continue progressing to the rear of and towards the latter by reason of the driving action of the adjacent threads. The broken thread gathers thus into a ball adjacent the braking member on the path of a pencil of light grazing the sheet of threads just before it reaches the braking member and sent out by a source of light towards a photo-cell releasing an alarm or the like mechanism whenever a thread breaks. The source of light and photo-cell are advantageoulsy rigid with the braking member so as to make the operation independent of the vibrations of the loom, warping system or the like machine.

United States Patent Fiorucci July 18, 1972 1541 ARRANGEMENT PROVIDED WITH A PHOTO-CELL AND CONTROLLING THE DETECTING MEANS AND THE sTO MOTION IN A LOOM UPON BREAKING OF A THREAD IN THE wARPING, WEAVING AND KNITTING SYSTEMS [72] Inventor: Georges P. Fiorucci, 69, Avenue de ll-lippodrome, 6 La Tour de Salvagny, France [22] Filed: June 22, 1970 [21] Appl. No.: 48,278

[30] Foreign Application Priority Data June 27, 1969 France ..692l900 [52] U.S. Cl ..l39/353, 28/51, 66/163, 250/219 [51] int. Cl. ..D03d 51/20, D02h 13/04, D04b 35/16 [58] Field ot'Search ..139/349, 352, 353, 370; 66/163; 250/219 R, 219 WE, 219 DF; 28/51 [56] References Cited UNITED STATES PATENTS 3,379,225 4/1968 lchimi et al. ..l39/353 2,373,854 4/1945 3,401,267 9/1968 2,233,483 3/1941 2,570,381 10/1951 Roughsedge et al. 2,711,093 6/1955 Edelman et ...66/163 3,530,690 9/1970 Nickell et al ..66/163 Primary Examiner.lames Kee Chi Attorney-McGlew and Toren 57 ABSTRACT In a loom or warping system, a safety arrangement is provided for operating machine-stopping or detecting means whenever a thread breaks. To this end, the sheet of parallel threads is constrained to pass over a braking member, in practice between frictionally acting parallel transverse bars, so that upon breaking of a thread beyond the braking member, said thread may continue progressing to the rear of and towards the latter by reason of the driving action of the adjacent threads. The broken thread gathers thus into a ball adjacent the braking member On the path of a pencil of light grazing the sheet of threads just before it reaches the braking member and sent out by a source of light towards a photo-cell releasing an alarm or the like mechanism whenever a thread breaks. The source of light and photo-cell are advantageoulsy rigid with the braking member so as to make the operation independent of the vibrations of the loom, warping system Or the like machine.

6 Claim, 5 Drawing Figures PATENTED JUL 1 81972 SHEET 1 OF 2 65011655 t'hohucq 3 If/ {Tm ARRANGEMENT PROVIDED WITH A PHOTO-CELL AND CONTROLLING THE DETECTING MEANS AND THE STOP MOTION IN A LOOM UPON BREAKING OF A THREAD IN THE WARPING, WEAVING AND KNITTING SYSTEMS BACKGROUND OF THE PRIOR ART Thread-break detectors are known in weaving looms, said detectors including a photo-cell which is normally energized by a pencil of light extending in parallelism with the sheet of threads and in proximity therewith, so that the modifications in the condition of the photo-cell may be resorted to whenever its energization is cut out or reduced upon a thread breaking on the downstream side of the light pencil and crossing the latter. In these known prior arrangements, steps are generally taken for the broken thread to cross the light pencil at a high speed as provided by projecting it by means of a sharp stream of compressed air. In such known plants, it may occur that the detecting means or stop motion are not operative by reason of the threads being too thin or crossing the light pencil too speedily. Furthermore, the circumambient atmosphere is laden with dust and with fluff produced either by knitting or else by the material which is being treated and this may lead to parasitic rays associated with the detecting light pencil, whereby the loom is stopped unconditionally.

SUMMARY OF THE INVENTION My invention has for its object to remove said defects and, although it resorts also to a photo-cell energized by a light pencil extending in parallelism with the sheet of threads and in proximity therewith, it covers an arrangement which differs from the preceding arrangements in its very principle since instead of allowing the thread to drop under the action of gravity or of urging it by means of an injection of compressed air at a more or less high speed across the light pencil, said arrangement holds the thread on the path of the pencil as an entangled comparatively thick ball of thread which does not move and which reliably starts the operation of the cell.

Accordingly my invention consists in laying immediately ahead of the point at which the sheet of threads passes over or under the light pencil and in proximity therewith a member braking the progression of said sheet by means of a slight friction exerted on the latter by two bars between which the latter slides. If one of the threads breaks inside the loom, such a friction stops the fraction of the thread remaining ahead of the bars, which fraction is carried along by reason of its contact with the adjacent threads which continue progressing, so that the broken thread coils up as it impinges on the hindrance formed by the bars and forms a ball in situ on the path of the light pencil. The photo-cell starts then the operation of the conventional safety means carried by the tensioning bars of the loom after a delay which is in fact comparatively short, but allows the thread thus balled up to acquire a sufficient size for it to be possible to insert it again in the fabric.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated, the photo-cell 6 and the source of light energizing said cell are positioned in a manner such that the pencil of light grazes the sheet of threads N progressing from the warp roller S towards the reed P. According to the operative conditions and chiefly according as to whether the thread is, depending on its count, lighter or heavier, it is of interest for the sheet of threads to pass underneath the light pencil as illustrated or else above the latter.

According to the inventionthere is provided immediately beyond the point at which the sheet passes in proximity with the pencil of light a braking system constituted by two bars 1 and 2 between which the threads are to slidingly progress, one of said bars being lined with felt or the like material having for its object to exercise a slight friction on the threads. In the example disclosed it is assumed that the stationary bar 1 is constituted merely by a metal tube serving as a support for the sheet, whereas the movable felt-coated bar 2 is urged slightly against the former bar either under the action of gravity or else of adjustable springs 3 wound round short rods 4 carried by the stationary bar 1. As clearly shown in FIG. 3, the operation of the knobs B screwed over the rods 4 allows the tensioning of the springs 3 to be adjusted. Of course, the reverse ar rangement may be resorted to, that is the lower bar may carry a felt coat.

In order to allow the sheet of threads to engage the reed, the bar 2 may be raised away from the stationary bar I by sliding along the rods 4. To this end, it is guided by the uprights M forming part of the frame of the loom and its two ends rest on eccentric members 7 revolvably carried in said uprights and controlled by the handles 7a.

Preferably and as illustrated in FIGS. 2 and 3, the rods 4 carried by the bar 1 and guiding the bar 2 are rigid respectively with the source of light 5 and with the photo-cell 6, so that the relative position of the bars and of the pencil of light impinging on the photo-cell may be perfectly unvarying and may not be subjected to any oscillation ascribable to the vibrations of the loom, which might lead to disturbances in the operation of the cell.

There is illustrated at 8 a screen carried by the supports provided for the source of light 5 and for the photo-cell 6, so as to form a cover extending above the luminous pencil and to cut out the action of the modifications in the ambient light produced by the sun or illuminating apparatus and by shadows.

FIGS. 4 and 5 illustrate the operation of the arrangement. In FIG. 4 wherein R designates the pencil of light, it is apparent that a thread f has just broken at fa beyond the friction line XX provided between the two bars bars I and 2. In FIG. 5, the upstream 'sectionfj' of the thread which has stopped at f, has gathered as a ball located exactly on the path of the light pencil R.

The improved arrangement according to the invention is applicable on all looms whether weaving looms, knitting looms, Raschel looms, chain looms, or warping means. It operates accurately with all kinds of threads, whether natural, artificial or synthetic in the execution of any fabric, whether open worked or otherwise, elastic, pleated, puffed, rippled, ladderproof, special and fancy Raschel fabrics. Means are advantageously provided for shifting the thread braking member transiently away from its operative position so as to allow the tying, leasing and insertion of the threads.

A series of looms equipped with arrangements according to the invention may be controlled from a control board for common supervision.

What I claim is:

I. In the thread feed of a fabric forming machine, such as a loom or the like, wherein a plurality of substantially parallel threads are drawn from a supply to a beam, in a common plane, and in which a light beam of a photoelectric device is directed across the threads in closely adjacent relation to the common plane to detect thread breakage, an improved safety system comprising a braking member engageable with said threads immediately adjacent said light beam and after the threads have passed said light beam; said braking member, upon breakage of a. thread beyond the braking member, stopping advance of the broken thread, by entraining of the broken thread by adjacent threads, to cause the broken thread to form a ball, at said braking member, in the path of said light beam.

2. A safety system as claimed in claim 1 wherein the threadbraking member operates through friction and includes two parallel bars-between which the sheet of threads is adapted to progress the operative surface of one of said bars being lined with felt.

3. A safety system as claimed in claim 1 wherein the threadbraking member operates through friction and includes two parallel bars between which the sheet of threads is adapted to progress, and means for adjusting the pressure between the two bars.

4. An arrangement as claimed in claim 1 comprising a support common to the thread-braking member, to the source of light and to the photo-cell whereby the relative position of the braking member with reference to the pencil of light is stationary and independent of the vibrations of the machine.

5. An arrangement as claimed in claim 1 comprising a screen extending above the path followed by the pencil of light and a common support for the source of light, for the photocell and for the screen.

6. An arrangement as claimed in claim 1 including means for transiently moving the thread-braking member away from the sheet of threads 

1. In the thread feed of a fabric forming machine, such as a loom or the like, wherein a plurality of substantially parallel threads are drawn from a supply to a beam, in a common plane, and in which a light beam of a photoelectric device is directed across the threads in closely adjacent relation to the common plane to detect thread breakage, an improved safety system comprising a braking member engageable with said threads immediately adjacent said light beam and after the threads have passed said light beam; said braking member, upon breakage of a thread beyond the braking member, stopping advance of the broken thread, by entraining of the broken thread by adjacent threads, to cause the broken thread to form a ball, at said braking member, in the path of said light beam.
 2. A safety system as claimed in claim 1 wherein the thread-braking member operates through friction and includes two parallel bars between which the sheet of threads is adapted to progress the operative surface of one of said bars being lined with felt.
 3. A safety system as claimed in claim 1 wherein the thread-braking member operates through friction and includes two parallel bars between which the sheet of threads is adapted to progress, and means for adjusting the pressure between the two bars.
 4. An arrangement as claimed in claim 1 comprising a support common to the thread-braking member, to the source of light and to the photo-cell whereby the relative position of the braking member with reference to the pencil of light is stationary and independent of the vibrations of the machine.
 5. An arrangement as claimed in claim 1 comprising a screen extending above the path followed by the pencil of light and a common support for the source of light, for the photo-cell and for the screen.
 6. An arrangement as claimed in claim 1 including means for transiently moving the thread-braking member away from the sheet of threads. 